“H2IK” is the fourth episode on ABC’s Defying Gravity. Something is wrong with the ship, can Donner figure out what’s going on? This episode is a little better than the last two, but it doesn’t seem like we are inching any closer to some big reveal.

**SPOILERS AHEAD**
The episode starts out with a classroom session with Paula and she talks about gravity on the ship. A student asked why their hair doesn’t fly all over the place while on the ship. Parts of the ship have natural gravity because it is generated by the ship’s rotors. In order to create artificial gravity on the other parts of the ship, the crew rely on their anti-gravity suits and a spray so they don’t float around. Zoe demonstrates the spray by spraying her hair and uses a magnet to show that her hair is magnetized. All of a sudden the power goes out on the ship. Donner checks it out and says that it could be a H2IK issue. Here is the rest of the episode highlights.

Ted talks to his wife Eve, and she asks how many times he has been back to Pod 4. He says 3 times and all he sees is a “Mars” storm.

There is a flashback and we find out that it is the 5th anniversary of the Mars disaster where two people were left behind including Donner’s girlfriend Sharon. This is why he doesn’t date astronauts.

We discover that Ajay was one of the engineers that built the Antares.

H2IK is a code that Ajay and his co-workers developed while working on the Antares project. It stands for “Hell if I know.” He lets Donner in on the code and tells him that whenever someone says the code it allows someone to step in and assist if they ever got stuck on an issue and need assistance.

Donner asks mission control where Ajay is, so that he can shed some light on the electrical problem on the ship. Ajay undergoes heart surgery, so he is unavailable.

Dr. Evram (on the ship) is going through withdrawal. We don’t know from what. In flashback we see the doctor has a large burn scar that covers most of his back.

Donner puts on a space suit and goes outside of the ship in order to figure out if the problem with the ship resides on the exterior of the ship.

Zoe and Nadia have a little tension toward each other. We find out that Nadia has been a “friend with benefits” to Donner for years but he hasn’t acted the same since Zoe has come along. Zoe then tells Nadia that they aren’t competing for him, and Nadia says that she (Zoe) is not competing with her (Nadia) but in fact she (Zoe) is competing with Sharon (the girl that Donner had to leave behind in the Mars disaster).

Back to Donner, he looks around the exterior of the ship and everything is fine and then he sees two astronauts covered in orange dirt. It is one man and one woman. The woman is Sharon.

In a flashback, the astronaut candidates, Donner, Ted, and Gross (mission director) are celebrating the Mars disaster anniversary and toasting to their failure as the candidates stated.

Back to the present. Sharon mouths to Donner that she misses him and she loves him. The two astronauts then jet upwards and Donner goes after them.

Zoe and Nadia try to talk to Donner over his com, but he doesn’t respond. Zoe then on a plea says “I need you” and “come back to me”. Donner hears and responds and he heads back and Nadia on a last note says that “men only listen when they want to” and Zoe just nods.

The doctor hits the ground and starts reliving a memory where he is in a war and on the battlefield he tries to save someone (I think it is his daughter) and they die before his eyes and he screams. The doctor suffers from post dramatic stress disorder. This is why he has been medicating himself and only Claire (the doctor back in mission control) knows this.

Now back to the problem on the ship. After failing to identify the problem, the mission control team go to Ajay who is in the hospital recovering from his surgery.

Ajay tells Donner to run the H2IK sequence and start from the beginning.

Donner lets the crew know what H2IK means and starts looking for the issue.

Donner figures out that the mag grav demonstration (Zoe’s hair and magnet experiment for Paula’s class) must’ve moved around some spare metal, and he finds a wrench stuck in the circuit area. Power is restored!

Afterward the crew demanded that Ajay be reinstated to the floor of mission control because they need him. Ajay is reinstated.